Chapter 1 Fundamentals - Seoul National University · 2018. 1. 30. · Chapter 1 Fundamentals...
Transcript of Chapter 1 Fundamentals - Seoul National University · 2018. 1. 30. · Chapter 1 Fundamentals...
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Chapter 1
Fundamentals
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Chapter 1 Fundamentals
Contents1.1 Scope of Fluid Mechanics
1.2 Historical Perspective
1.3 Physical Characteristics of the Fluid State
1.4 Units and Density
1.5 Compressibility, Elasticity
1.6 Viscosity
1.7 Surface Tension, Capillarity
1.8 Vapor Pressure
Objectives
- Present concept of fluidity
- Introduce fundamental properties of fluid
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1.1 Scope of Fluid Mechanics
• Problems of water supply
flood prevention
navigation need to know fluid phenomena
water power
irrigation
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1.2 Historical Perspective
• d'Alembert (1744)
"The theory of fluids must necessarily be based upon experiment"
• d'Alembert paradox theory - ideal, inviscid fluid
practice - real fluid (viscous)
• Two schools theoretical group → hydrodynamics
practical group → hydraulics
• Navier and Stokes
→ general equations for viscous fluid → equation of motion
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1.2 Historical Perspective
[Re] Navier-Stokes equation
Claude-Louis Navier (1785-1836, French engineer) and George Gabriel
Stokes (1819-1903, UK mathematician & physicist)
- one continuity equation + three momentum equations
- model the weather, ocean currents, water flow in a pipe, the air's flow
around a wing, and motion of stars inside a galaxy
- design of aircraft and cars, the study of blood flow, the design of power
stations, the analysis of pollution,
- exact solution - one of the seven most important open problems in
mathematics
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1.2 Historical Perspective
• New problems in modern times
- Dispersion of man's wastes in lakes, rivers, and oceans
→ Environmental Fluid Mechanics (Hydraulics)
• state: solid
liquid increasing spacing increasing inter
fluid gaseous and latitude of molecular cohesive
plasma particle motion force
• fluid – continuum → no voids or holes
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1.3 Physical Characteristics of the Fluid State
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1.3 Physical Characteristics of the Fluid State
stressstrain
solid fluid
tension
elastic deformation
→ permanent distortion
unable to support tension
(surface tension)
compressionelastic deformation
(compressible fluid)
shear (tangential forces)
permanent distortion or flo
w (change shape) to infini
tesimal shear stress
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1.3 Physical Characteristics of the Fluid State
dvdy
τ µ=
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1.3 Physical Characteristics of the Fluid State
stress
real fluid (viscous fluid)
ideal fluid
(non-viscous
fluid)
in motion at restat rest and
in motion
compression
(pressure)○ ○ ○
shear ○ × ×
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1.3 Physical Characteristics of the Fluid State
incompressible fluid compressible fluid
① Compressibility is of small important. ① Compressibility is predominant.
② Liquids and gases may be treated
similarly.
② Behavior of liquids and gases is quite
dissimilar.
③ Fluid problems may be solved with
the principles of mechanics.
③ Thermodynamics and heat transfer
concepts must be used as well as
principles of mechanics.
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1.3 Physical Characteristics of the Fluid State
• Properties of pressure (compression)
① Pressure must be transmitted to solid boundaries normal to those
boundaries.
② At a point, pressure has the same magnitude in all directions.
→ Pressure is a scalar quantity.
* Fluid does not resist any small shearing stress → "Flow occurs"
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1.3 Physical Characteristics of the Fluid State
Weight.W Volγ=
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1.3 Physical Characteristics of the Fluid State
0F∑ =
(a)1 3 sin 0xF p dz p ds θ∑ = − =
2 3/ 2 cos 0zF p dx gdxdz p dsρ θ∑ = − − =
[Pf]
Apply Newton's law for static equilibrium
(b)
sindz ds θ=cosdx ds θ=
1 3 1 3( ) : sin sin 0a p ds p ds p pθ θ∴ − = → =
Substitute following relations into Eq. (a) & (b)
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1.3 Physical Characteristics of the Fluid State
2 3( ) : cos cos cos 02dzb p ds g ds p dsθ ρ θ θ− − =
2 312
p p gdzρ∴ = +
0dz → 2 3p p≈
1 2 3p p p∴ = = ( 0)dx dz= =
As then
at a point
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1.4 Units and Density
• SI units - SI system – metric system
f- Frequency ( ): hertz (HZ = s-1)
F
F ma=
2/ /a v t L t= = 2Lt− /v L t= 1Lt−
21kg m/s 1N( )F Newton∴ → ⋅ =
• Force,
→ introduce Newton's 2nd law of motion
Force = mass × acceleration
(m/s2)
(m/s)
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1.4 Units and Density
Dimension SI unit English system (FSS)
Length (L) metre (m) feet (ft)
Mass (M) kilogram (kg) slug (-)
Time (t) second (s) second (s)
Temp. (T) kelvin (K) degree Rankine (°R)
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1.4 Units and Density
E2 2kg m /s ( )E FL J Joule= → ⋅ =
P2 3/ / kg m sP E t J s= → = ⋅
p ,σ τ2 2/ N/m Pa (pascal) kg/m sp F A= → = = ⋅
T
• Energy, (work)
• Power,
• Pressure, ; Stress,
• Temperature, : degree Celsius (°C)
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1.4 Units and Density
ρ
3kg/mMV
ρ = →
• Density,
= mass per unit volume
~ depends on the number of molecules per unit of volume
~ decreases with increasing temperature
γ
3 2 2N/m kg/m sWV
γ = → = ⋅
• Specific weight (weight density),
= weight (force) per unit volume
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1.4 Units and Density
(1.1)
W Mg=g
gγ ρ∴ =
[Re](Newton’s 2nd law of motion)
= acceleration due to gravity
1/ ρ• Specific volume=volume per unit mass=
• Specific gravity, s.g. , ~ r. d. (relative density)
= ratio of density of a substance to the density of water at a specified
temperature and pressure
. . f fw w
s gρ γρ γ
= =
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1.4 Units and Density
[Re] s.g. of sea water = 1.03
s.g. of soil = 2.65
s.g. of mercury = 13.6
( )F ( )M• Advantage of SI system and English FSS system
① It distinguishes between force and mass .
② It has no ambiguous definitions.
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1.4 Units and Density
SI English system
1,000 kg/m3 1.94 slugs/ft3
9,806 N/m3 62.4 lb/ft3
9.81 m/s2 32.2 ft/s2
ρ
γ
g
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1.4 Units and Density
α
β,γ Γ
,δ ∆εζη
,θ Θ
ι
• Greek Alphabet
Alpha angle
Beta [beitə] angle
Gamma specific weight, circulation
Delta thickness of boundary layer
Epsilon eddy viscosity, height of surface roughness
Zeta
Eta
Theta
Iota [aioutə]
Kappa [kæpə]κ
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1.4 Units and Density
,λ Λ
µ
νξοπ
ρ
,σ ∑
τ
Lambda
Mu [mju:] dynamic viscosity
Nu kinematic viscosity
Xi [gzai, ksai] vorticity
Omicron
Pi [pai]
Rho mass density
Sigma Sigma Xi, Scientific Research Society, 1886
honor society for scientists & engineers
Tau shear
Upsilon,υ ϒ
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1.4 Units and Density
,ϕ Φ
χ
,ψ Ψ
,ω Ω
Phi [fai] Phi Beta Kappa
Chi [kai]
Psi [psai, sai] stream function
Omega angular velocity
• Prefixes
E exa 1018
P peta 1015
T tera 1012
G giga 109
M mega 106
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1.4 Units and Density
µ
M mega 106
k kilo 103
h hecto 102
da deca 101
d deci 10-1
c centi 10-2
m milli 10-3
micro 10-6
n nano 10-9
p pico 10-12
f femto 10-15
a atto 10-18
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1.5 Compressibility, Elasticity
• Elastic behavior to compression
• Compressibility ≡ change in volume due to change in pressure
solid - modulus of elasticity, E (N/m2)
fluid - bulk modulus
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1.5 Compressibility, Elasticity
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1.5 Compressibility, Elasticity
1
dVdpV
∝1
dVdp EV
→ = −
1
1
( , )dp dpE V const fn p TdV dVV
= − = − ≠ = → p E↑ → ↑
1
1 1dVCE V dp
= = −
• Stress-strain curve (E↑, difficult to compress)
= modulus of compressibility (m2/N)
Minus means that increase in
pressure causes decrease in
volume
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1.5 Compressibility, Elasticity
, 1E C= ∞ ρ
[Re] large E/small C → less compressible
• incompressible fluid (inelastic):
→ constant density =const.
~ water
• compressible fluid
→ changes in density → variable density
~ gas
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1.5 Compressibility, Elasticity
Pressure
106 N/m2
Temperature, °C
0° 20° 50° 100° 150°
0.1 1950 2130 2210 2050
10.0 2000 2200 2280 2130 1650
30.0 2110 2320 2410 2250 1800
100.0 2530 2730 2840 2700 2330
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1.5 Compressibility, Elasticity
E
E
- increases as pressure increases.
- is maximum at about 50 °C.
→ The water has minimum compressibility at about 50 °C.
1dpE VdV
= −
1
V pV E∆ ∆
≈ −
2 1 2 1
1
V V p pV E− −
≈ −
• For the case of a fixed mass of liquid at constant temperature
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1.5 Compressibility, Elasticity
Compressibility Modulus of Elasticity, E (kPa)
steel 1/80 of water water 2,170,500
mercury 1/12.5 of water sea water 2,300,000
nitric acid 6 of water mercury 26,201,000
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1.5 Compressibility, Elasticity
62,200 10 PaE = ×6
2 1 7 10 Pap p= + ×
2 1 2 1
1
0.0032V V p pV E− −
∴ ≈ − = −
2 1(1 0.0032)V V∴ = −
0.3%V∆ ≈
[Ex] For water; @ 20˚C
decrease
→ water is incompressible
63
7 10 Pa 70101.3 10 Pap×∆ = ≈
×기압
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1.6 Viscosity
[Re] From Wikipedia
Viscosity is a measure of the resistance of a fluid which is being
deformed by either shear stress or tensile stress.
Viscosity ~ "thickness" or "internal friction"
▪ water ~ "thin", having a lower viscosity
▪ honey ~ "thick", having a higher viscosity
The less viscous the fluid is, the greater its ease of movement (fluidity).
Viscosity describes a fluid's internal resistance to flow and may be
thought of as a measure of fluid friction.
dvdy
τ µ=
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1.6 Viscosity
For example, high-viscosity felsic magma will create a tall, steep
stratovolcano, because it cannot flow far before it cools, while low-
viscosity mafic lava will create a wide, shallow-sloped shield volcano.
All real fluids (except superfluids) have some resistance to stress and
therefore are viscous, but a fluid which has no resistance to shear stress
is known as an ideal fluid or inviscid fluid.
[Re] super fluid – a fluid having frictionless flow, and other unusual
properties
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1.6 Viscosity
• Two types of fluid motion (real fluid)
1) laminar flow:
- viscosity plays a dominant role
- fluid elements or particles slide over each other in layers (laminar)
- molecular diffusion
[Ex] flow in a very small tube, a very thin flow over the pavement, flow in
the laminar flow table
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1.6 Viscosity
Re Vdν
=
where V = flow velocity; d = characteristic length; n = kinematic viscosity
Diameter of pipe,Depth of stream
2) turbulent flow:
- random or chaotic motion, eddies of various sizes are seen
- common in nature (streams, rivers, pipes)
- large scale mixing between the layers
• Reynolds number
[Ex] flows in the water supply pipe, flows in the storm sewer pipe, flows in
the and canals and streams
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1.6 Viscosity
• Reynolds experiments
laminar flow: Re < 2,100
transition: 2,100 4,000
The same fluid withdifferent velocity
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1.6 Viscosity
Spiralsecondaryflow
Secondaryflow
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1.6 Viscosity
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1.6 Viscosity
cubestreamline
source
sink
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1.6 Viscosity
Smoothsurface
Eddyingmotion
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1.6 Viscosity
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1.6 Viscosity
Symmetric shape,No separation
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1.6 Viscosity
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1.6 Viscosity
Separation, eddyformation
Growthof eddy
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1.6 Viscosity
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1.6 Viscosity
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1.6 Viscosity
• laminar flow
2 1d d dvdt dv dtdy dy dy−
= = = yxdGdyζτ =
2 2 1 1
2 1 2 1
;( )
d v dt d v dtd d v v dt
= =− = −
• strain = relative displacement [Cf] solid mechanics
[Re] total angular displacement
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1.6 Viscosity
no velocity at theboundary (no slip)
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1.6 Viscosity
τ• Experiment has shown that, in many fluids, shearing (frictional) stress
per unit of contact area, is proportional to the time rate of relative
strain.
/dv dvdt dtdy dy
τ∴ ∝ =
dvdy
τ µ= →
(velocity gradient)
Newton’s equation of viscosity (1.2)
µwhere = coefficient of viscosity
= dynamic (absolute) viscosity
Large → sticky, difficult to flowµ
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1.6 Viscosity
• viscosity = measure of fluid's resistance to shear or angular
deformation
= internal resistance of a fluid to motion (fluidity)
[Re] Friction forces result from
- cohesion for liquid
- momentum interchange between molecules for gas
[Re] angular deformation due to tangential stress
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1.6 Viscosity
dy
x
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1.6 Viscosity
du duu y t u t y tdy dy
= + ∆ ∆ − ∆ = ∆ ∆
/du duy t y tdy dy
= ∆ ∆ ∆ = ∆
• rate of angular deformation
(i) displacement of AB relative to CD
(ii) angular displacement of AC
(iii) time rate of angular deformation
/du dut tdy dy
= ∆ ∆ =
dvdy
τ µ=
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1.6 Viscosity
µ• dynamic viscosity,
/F Aτ =
[ ] 2 2 1 2 2/ kg/(m s ) PaMLT L ML Tτ − − − = = ⋅ = 1
1dv LT Tdy L
−− = =
[ ]1 2
1 1 21/ kg/m s N s / m Pa s
dv ML T ML Tdy T
µ τ− −
− −−
∴ = = = = ⋅ = ⋅ = ⋅
11 ( ) 10 Pa spoises Poiseuille −⇒ = ⋅
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1.6 Viscosity
ν• kinematic viscosity,µνρ
=
[ ]1 1
2 1 23 m /s
ML T L TML
ν− −
−−
= = =
(1.3)
1 m2/s = 104 stokes =106 centistokes
,τ µ
τ τ
• Remarks on Eq. (1.2)
① are independent of pressure. [Cf] friction between two moving
solids
② Shear stress (even smallest ) will cause flow (velocity gradient).
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1.6 Viscosity
0 0dvdy
τ= → = µregardless of
③ Shearing stress in viscous fluids at rest will be zero.
dvdy
≠ ∞ τ→ ≠ ∞④ At solid boundary, ( (no infinite shear))→ Infinite shearing stress between fluid and solid is not possible.
⑤ Eq. 1.2 is limited to laminar (non-turbulent) fluid motion in which
viscous action is predominant.
[Cf] turbulent flow
εε µ
dvdy
τ ε=
where = eddy viscosity
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1.6 Viscosity
⑥ Velocity at a solid boundary is zero.
→ No slip condition (continuum assumption)
• Newtonian and non-Newtonian fluids
i) Newtonian fluid ~ water
ii) Non-Newtonian fluid ~ plastic, blood, suspensions, paints, polymer
solutions → rheology
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1.6 Viscosity
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1.6 Viscosity
1dvdy
τ τ µ− =
ndvKdy
τ
=
1τ
1n >
1n <
• Non-Newtonian fluid
1) plastic, = threshold
2) Shear-thickening fluid
Shear-thinning fluid
• Couette flow: laminar flow in which the shear stress is constant
thin fluid film between two large flat plates
thin fluid film between the surfaces of coaxial cylindersdv Vdy h
=
Vh
τ µ∴ =
~ linear velocity gradient
~ constant
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1.6 Viscosity
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1.6 Viscosity
( ) dvdy
τ µ ε= +
ε
• Turbulent flow
= eddy viscosity = viscosity due to turbulent factor
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1.6 Viscosity
gas liquid
main cause of
viscosity
exchange of molecule's momentum →
interchange of molecules between
the fluid layers of different velocities
intermolecular cohesion
effect of
temperature
variation
temp↑ → molecular activity↑
→ viscosity↑ → shearing stress↑
temp↑ → cohesion↓
→ viscosity↓ → shear stress↓
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1.6 Viscosity
Two layers tendto stick togetheras if there is some viscosity between two.
[Re] Exchange of momentum
fast-speed layer (FSL)
molecules from FSL speed up molecules in LSL
molecules from LSL slow down molecules in FSL
low-speed layer (LSL)
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1.6 Viscosity
mv
1) exchange of momentum : exchange momentum in either direction from
high to low or from low to high momentum due to random motion of
molecules
2) transport of momentum : transport of momentum from layers of high
mome
(high velocity, ) to layers of low momentum
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1.7 Surface Tension, Capillarity
nf
σ
• surface tension
- occur when the liquid surfaces are in contact with another fluid (air) or
solid
- (relative sizes of intermolecular cohesive and adhesive forces to
another body)
- as temp↑ → cohesion↓ → ↓ ☞ Table A2.4b, p. 694
• some important engineering problems related to surface tension
- capillary rise of liquids in narrow spaces
- mechanics of bubble formation
- formation of liquid drops
- small models of larger prototype → dam, river model
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1.7 Surface Tension, Capillarity
σ /F L• surface tension, ( , N/m)- force per unit length
- force attracting molecules away from liquid
0F∑ = , , ,a b c d
0( ) 2 sin 2 sinip p dxdy dy dxσ α σ β− = +
Consider static equilibrium
(forces normal to the element )
where pi = pressure inside the curvature; po = pressure inside the
curvature1
sin ,2dxR
α =2
sin2dyR
β = [ ]12( sin )dx R α=
01 2
1 1ip p R R
σ
∴ − = +
(1.4)
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1.7 Surface Tension, Capillarity
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1.7 Surface Tension, Capillarity
• Cylindrical capillary tube
- due to both cohesion and adhesion
cohesion < adhesion → rise (water)
cohesion > adhesion → depression (mercury)
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1.7 Surface Tension, Capillarity
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1.7 Surface Tension, Capillarity
1 2R R R= = ≈
0p hγ= −
0ip =
For a small tube, given conditions are as follows
(liquid surface section of sphere) ← Ch. 2
(hydrostatic pressure)
(atmospheric)
01 2
1 1ip p R R
σ
− = + 2h
Rγ σ∴ =
Substitute above conditions into Eq. 1.15: (1.4)
cosr R θ=2 2 cos
/ cosh
r rσ θγ σ
θ∴ = =
2 coshr
σ θγ
=
By the way,
(1.5)
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1.7 Surface Tension, Capillarity
h r hθr ≤
in which = capillary rise → ↑ → ↓
= angle of contact
= radius of tube 2.5 mm for spherical form
12r > h[Ex] water and mercury → Fig. 1.11
If mm, is negligible for water.
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1.7 Surface Tension, Capillarity
cohesion > adhesion
→ depression
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1.7 Surface Tension, Capillarity
• Pressure measurement using tubes in hydraulic experiments
→ Ch.2 manometer
~ capillarity problems can be avoided entirely by providing tubes large
enough to render the capillarity correction negligible.
• Fomation of curved surface, droplet
- At free liquid surface contacting the air, cohesive forces at the outer
layer are not balanced by a layer above.
→The surface molecules are pulled tightly to the lower layer.
→Free surface is curved.
[Ex] Surface tension force supports small loads (water strider).
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1.7 Surface Tension, Capillarity
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1.7 Surface Tension, Capillarity
0 1.0ip p− =
0.0728σ =At 20°C, N/m ← App. 2
[IP 1.10] For a droplet of water (20 °C), find diameter of droplet
Given: kPa
01 2
1 1 2ip p R R R
σσ
− = + =
∴1R⋅
0.000146m 0.146mmR∴ = = 0.292d→ =
[Sol]
(1.4)
1×103 N/m2 = 2(0.0728)
mm
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1.7 Surface Tension, Capillarity
[IP 1.11] Find height of capillary rise in a clean glass tube of 1 mm
diameter if the water temperature is 10°C or 90°C.
[Sol]
From App. 2 Table A 2.4b;
σ γ
σ γ@ 10°C =0.0742 N/m, = 9.804 kN/m3
@ 90°C =0.0608 N/m, = 9.466 kN/m3
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1.7 Surface Tension, Capillarity
Use Eq. 1.16
For water, 0θ =
2 coshr
σ θγ
=
1̀02(0.0742)(1) 0.030m=30mm
9804(0.0005)h∴ = =
902(0.0608)(1) 0.026m=26mm
9466(0.0005)h = =
(1.5)
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1.8 Vapor Pressure
• vapor pressure = partial pressure exerted by ejected molecules of liquid
→ Table A2.1 and A2.4b
• liquids ~ tend to vaporize or evaporate due to molecular thermal
vibrations (molecular activity)
→ change from liquid to gaseous phase
temperature↑ → molecular activity↑ → vaporization↑ → vapor pressure↑
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1.8 Vapor Pressure
55.2 kPavp =2.34 kPavp =
0.00017 kPavp =
• volatile liquids:
~ easy to vaporize → high vapor pressure
gasoline: at 20 °C
water: at 20 °C
mercury: at 15.6 °C
• mercury : low vapor pressure and high density = difficult to vaporize
→ suitable for pressure-measuring devices
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1.8 Vapor Pressure
In the interior and/or boundariesof a liquid system
High velocity region
• Cavitation: App. 7 (p. 672)
In a flow fluid wherever the local pressure falls to the vapor pressure of
the liquid, local vaporization occurs.
→ Cavities are formed in the low pressure regions.
→ The cavity contains a swirling mass of droplets and vapor.
→ Cavities are swept downstream into a region of high pressure.
→ Then, cavities are collapses suddenly.
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1.8 Vapor Pressure
→ surrounding liquid rush into the void together
→ it causes erosion (pitting) of solid boundary surfaces in machines, and
vibration
→ boundary wall receives a blow as from a tiny hammer
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1.8 Vapor Pressure
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1.8 Vapor Pressure
• Prevention of cavitation
~ cavitation is of great importance in the design of high-speed hydraulic
machinery such as
turbines, pumps, in the overflow and underflow structures of high dams,
and in high-
speed motion of underwater bodies (submarines, hydrofoils).
→ design improved forms of boundary surfaces
→ predict and control the exact nature of cavitation → set limits
Bodycavitation
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1.8 Vapor Pressure
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1.8 Vapor Pressure
atm vp p≤
• Boiling:
= rapid rate of vaporization caused by an increase in temperature
= formation of vapor bubbles throughout the fluid mass
~ occur (whatever the temperature) when the external absolute pressure
imposed on the
liquid is equal to or less than the vapor pressure of the liquid
~ boiling point = f (imposed pressure, temp.)
→ boiling occurs
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1.8 Vapor Pressure
altitude
(El. m)
Temp.
(°C)
(kPa),
absolute
(kPa),
absolute
boiling point
(°C)remark
m.s.l. 100 101.3 101.3 100
12,000 60 19.9 19.4 60 undercooked
vp atmp
Table A2.4b
Table A2.5b
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1.8 Vapor Pressure
vp• Evaporation: When the space surrounding the liquid is too large, the
liquid continues to
vaporize until the liquid is gone and only vapor remains at a pressure
less than or equal.
[IP 1.12] For a vertical cylinder of diameter 300 mm, find min. force that
will cause the water boil.
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1.8 Vapor Pressure
Patm=100 kpa
Water @ 70˚C
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1.8 Vapor Pressure
vp
'vp p≤
' 100 31.16FpA
∴ = − =
2(0.3)(100 31.16) 4.87 kN4
F π∴ = − =
[Sol] From Table A2.4b; =31.16 kPa at 70 °C
=31.16, For water to boil;
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1.8 Vapor Pressure
Homework Assignment # 1
Due: 1 week from today
Prob. 1.2
Prob. 1.10
Prob. 1.27
Prob. 1.46
Prob. 1.49
Prob. 1.58
Prob. 1.69
Prob. 1.72
Prob. 1.82
Chapter 1Chapter 1 Fundamentals1.1 Scope of Fluid Mechanics��1.2 Historical Perspective��1.2 Historical Perspective��1.2 Historical Perspective��1.3 Physical Characteristics of the Fluid State��1.3 Physical Characteristics of the Fluid State��1.3 Physical Characteristics of the Fluid State��1.3 Physical Characteristics of the Fluid State��1.3 Physical Characteristics of the Fluid State��1.3 Physical Characteristics of the Fluid State��1.3 Physical Characteristics of the Fluid State��1.3 Physical Characteristics of the Fluid State��1.3 Physical Characteristics of the Fluid State��1.4 Units and Density��1.4 Units and Density��1.4 Units and Density��1.4 Units and Density��1.4 Units and Density��1.4 Units and Density��1.4 Units and Density��1.4 Units and Density��1.4 Units and Density��1.4 Units and Density��1.4 Units and Density��1.5 Compressibility, Elasticity��1.5 Compressibility, Elasticity��1.5 Compressibility, Elasticity��1.5 Compressibility, Elasticity��1.5 Compressibility, Elasticity��1.5 Compressibility, Elasticity��1.5 Compressibility, Elasticity��1.5 Compressibility, Elasticity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.6 Viscosity��1.7 Surface Tension, Capillarity��1.7 Surface Tension, Capillarity��1.7 Surface Tension, Capillarity��1.7 Surface Tension, Capillarity��1.7 Surface Tension, Capillarity��1.7 Surface Tension, Capillarity��1.7 Surface Tension, Capillarity��1.7 Surface Tension, Capillarity��1.7 Surface Tension, Capillarity��1.7 Surface Tension, Capillarity��1.7 Surface Tension, Capillarity��1.7 Surface Tension, Capillarity��1.7 Surface Tension, Capillarity��1.8 Vapor Pressure��1.8 Vapor Pressure��1.8 Vapor Pressure��1.8 Vapor Pressure��1.8 Vapor Pressure��1.8 Vapor Pressure��1.8 Vapor Pressure��1.8 Vapor Pressure��1.8 Vapor Pressure��1.8 Vapor Pressure��1.8 Vapor Pressure��1.8 Vapor Pressure��1.8 Vapor Pressure��